The proposed research is designed to determine the influence of dietary selenium on the transfer of dietary mercury into eggs of chickens and quail, into milk of goats and into selected body tissues of these three species. In addition, the effect of selenium on apparent absorption and patterns of excretion of mercury by chickens, quail and goats will be determined, and the sub-cellular distribution of mercury in selected body tissues will be measured. The approach will involve the use of individual animals kept in metabolism cages to facilitate quantitative collection of eggs, milk and excreta. Dietary treatments will be comprised of a complete factorial arrangement of selected levels of sodium selenite and methyl mercuric chloride. The radioisotope, CH3 2O3 HgCl, will also be used to assist in tracing the metabolism of mercury. The research will yield information about the significance of a selenium by mercury interrelationship which may affect the rate and magnitude of mercury accumulation in three animal products intended for human consumption--eggs, meat and milk. Also, the information obtained will lead to a better understanding of some fundamental aspects of the selenium by mercury interrelationship as related to absorption, metabolism and excretion of mercury by three species of animals.